"However, Sam's symptoms were having more of an impact on his health and social wellbeing, and there was no further possibility of improving his overall welfare," said Mr Basson.
"Animal welfare is our top priority, so the decision to euthanise Sam was made in his best interests."
"Zoo staff will miss Sam's calm presence, and his peaceful attitude among the rest of the chimpanzee community."
Sam was born at Wellington Zoo in 1978, and has fathered a number of chimpanzees. He was often known for his penchant for blankets or sacks.
"Sam was a sun-smart chimpanzee, always first to nab a blanket to cover up from the sun - or to wrap up warm on cooler days," said senior zoo keeper Harmony Wallace.
"He was easy to distinguish from the other chimps with his large presence, and always being the first one up for food. Always a lover, never a fighter - it's not surprising that he didn't ever make a bid for the alpha spot, but his loss will be noted by the other chimpanzees."
Chimpanzees have a complex social structure, and while Sam was a low-key member of the community, it is likely that his passing will mean further changing of the dynamics for his community.
Chimpanzees are an endangered species due to loss of habitat and poaching for bush meat and pet trades. Wellington Zoo is a member of the Jane Goodall Institute - which works to protect chimpanzees and other primates by supporting sanctuaries, reduce illegal animal trafficking, and education to protect endangered apes in the wild.
What is dilated cardiomyopathy?
• Dilated cardiomyopathy is a slow progressive disease of the heart muscle, which reduces the heart's ability to beat and contract.
• Wellington Zoo is home to 11 Chimpanzees, which is one of the largest chimpanzee communities in Australasia.